This patch is empty according to splinter: https://bugzilla.mozilla.org/page.cgi?id=splinter.html&bug=717181&attachment=771171 But the content is actually bigger. The "diff" view shows everything: https://bugzilla.mozilla.org/attachment.cgi?id=771171&action=diff This is the raw file: https://bug717181.bugzilla.mozilla.org/attachment.cgi?id=771171 What sounds unusual here is the "diff -r xxxxxx -r yyyyyy foo.cpp".

No... I'm sorry I think this is my mistake. About 30% of the files I work on in mozilla-central have trailing whitespace, and my vim is set up to autoclear those, which gives _me_ whitespace errors in my diffs. I got tempted with manually editing the .patch files by removing the hunks with only whitespace diffs, and that's what was creating this mess. You should consider have your diff tool break along with your review tool, so if someone else tries something like I did they'd see that something is obviously wrong. Else I'd say your review tool is fine. I'd wish there was a way to tell hg to ignore whitespace diffs in patches. Git does it...

by removing all trailing whitespace from the generated diff, the end result is indeed an invalid diff. unfortunately bugzilla's "diff" tool uses a completely different approach to parsing patches than splinter, and much more tolerant. (In reply to Mina Almasry from comment #1) > I'd wish there was a way to tell hg to ignore whitespace diffs in patches. > Git does it... https://developer.mozilla.org/en-US/docs/Mercurial_FAQ#How_do_I.C2.A0get_a_diff_-w.3F